Switchable parallel configurations for modular battery system

Abstract

A modular battery system includes a battery pack with multiple battery modules electrically interconnected via a plurality of electrical cables. A plurality of switches selectively connects the multiple battery modules. A direct current (DC) charge connector is configured to electrically connect the battery pack to an off-board DC fast-charging station, via the plurality of electrical cables. The pack circuit is adapted to switch between a first configuration and a second configuration based on a respective position of the plurality of switches. A controller is configured to select the respective position of each of the plurality of switches to transition the pack circuit between the first configuration and the second configuration, in response to input signals indicative of a requested operating mode of the battery pack. The first configuration provides three parallel electrical pathways, and the second configuration provides two parallel electrical pathways.

What is claimed is: 
     
         1 . A modular battery system comprising:
 a battery pack having multiple battery modules and a plurality of electrical cables, the multiple battery modules being electrically interconnected via the plurality of electrical cables in a pack circuit, the multiple battery modules being divided into a first group, a second group, a third group and a fourth group;   a direct current (DC) charge connector configured to electrically connect the battery pack to an off-board DC fast-charging station, via the plurality of electrical cables, the battery pack being selectively connectable to a propulsion output;   a plurality of switches selectively connecting the multiple battery modules, the pack circuit being adapted to switching between a first configuration and a second configuration based on a respective position of the plurality of switches;   a controller having a processor and tangible, non-transitory memory on which instructions are recorded, the controller being adapted to select the respective position of the plurality of switches to transition the pack circuit between the first configuration and the second configuration, in response to input signals indicative of a requested operating mode of the battery pack;   wherein respective battery cells in the pack circuit are arranged in a combination of series and parallel interconnections; and   wherein the first configuration provides three parallel electrical pathways, and the second configuration provides two parallel electrical pathways, the parallel electrical pathways referring to individual ones of the respective battery cells arranged in parallel, or groups of the respective battery cells arranged in parallel.   
     
     
         2 . The system of  claim 1 , wherein the first configuration represents a propulsion mode, and the second configuration represents a charging mode. 
     
     
         3 . The system of  claim 1 , wherein the first configuration provides a propulsion power of about 400 volts and the second configuration provides a charging power of about 600 volts. 
     
     
         4 . The system of  claim 1 , wherein the plurality of switches includes:
 a first load switch configured to electrically connect the pack circuit to a positive leg of the propulsion output;   a second load switch configured to electrically connect the pack circuit to a negative leg of the propulsion output;   a first charge switch configured to electrically connect the pack circuit to the positive leg of the DC charge connector; and   a second charge switch configured to electrically connect the pack circuit to the negative leg of the DC charge connector.   
     
     
         5 . The system of  claim 1 , wherein:
 the first group includes two modules positioned at a negative end of the pack circuit, the fourth group including another two modules positioned at a positive end of the pack circuit; and   the second group and the third group respectively include a single module positioned in a middle of the pack circuit.   
     
     
         6 . The system of  claim 5 , wherein:
 the first group includes one-third of respective battery cells in the pack circuit;   the fourth group includes another one-third of the respective battery cells in the pack circuit; and   the second group and the third group together include a remaining one-third of the respective battery cells of the pack circuit.   
     
     
         7 . The system of  claim 5 , wherein the plurality of switches includes a central switch configured to electrically connect, when in a respective closed position:
 a respective positive leg of the second group to the respective positive leg of the first group; and   a respective negative leg of the fourth group to the respective positive leg of the first group.   
     
     
         8 . The system of  claim 7 , wherein the first configuration is achieved when:
 the central switch is in the respective closed position;   a first load switch and a second load switch electrically connect the pack circuit to the propulsion output;   the respective negative leg of the second group is selectively connected to the propulsion output; and   the respective positive leg of the third group is selectively connected to the propulsion output.   
     
     
         9 . The system of  claim 7 , wherein the second configuration is achieved when:
 the central switch is in a respective open position;   a first charge switch and a second charge switch electrically connect the pack circuit to the DC charge connector;   the respective positive leg of the first group is selectively connected to the respective negative leg of the second group; and   the respective positive leg of the third group to the respective negative leg of the fourth group.   
     
     
         10 . The system of  claim 7 , wherein:
 the plurality of switches includes a first two-way switch having two closed positions;   in one of the two closed positions, the first two-way switch is configured to electrically connect the respective negative leg of the second group to the propulsion output; and   in another of the two closed positions, the first two-way switch is configured to electrically connect the respective positive leg of the first group to the respective negative leg of the second group.   
     
     
         11 . The system of  claim 7 , wherein:
 the plurality of switches includes a second two-way switch having two closed positions;   in one of the two closed positions, the second two-way switch is configured to electrically connect the respective positive leg of the third group to the propulsion output; and   in another of the two closed positions, the second two-way switch is configured to electrically connect the respective positive leg of the third group to the respective negative leg of the fourth group.   
     
     
         12 . The system of  claim 1 , wherein at least one of the plurality of switches is an electro-mechanical contactor. 
     
     
         13 . The system of  claim 1 , wherein at least one of the plurality of switches includes a solid-state switch and/or a diode. 
     
     
         14 . A motor vehicle comprising:
 a battery pack having multiple battery modules and a plurality of electrical cables, the multiple battery modules being electrically interconnected via the plurality of electrical cables in a pack circuit, the battery pack being selectively connectable to a propulsion output for generating propulsion power for the vehicle;   wherein the battery pack includes:
 a direct current (DC) charge connector configured to electrically connect the battery pack to an off-board DC fast-charging station, via the plurality of electrical cables, the multiple battery modules being divided into a first group, a second group, a third group and a fourth group; 
 a plurality of switches selectively connecting the multiple battery modules, the pack circuit being adapted to switching between a first configuration and a second configuration based on a respective position of the plurality of switches; 
   a controller configured to select the respective position of each of the plurality of switches to transition the pack circuit between the first configuration and the second configuration, in response to input signals indicative of a requested operating mode of the battery pack; and   wherein the respective battery cells in the pack circuit are arranged in a combination of series and parallel interconnections;   wherein the first configuration provides three parallel electrical pathways, and the second configuration provides two parallel electrical pathways, the parallel electrical pathways referring to individual ones of the respective battery cells arranged in parallel, or groups of the respective battery cells arranged in parallel.   
     
     
         15 . The vehicle of  claim 14 , wherein:
 the first group includes two modules positioned at a negative end of the pack circuit, the fourth group including two modules positioned at a positive end of the pack circuit; and   the second group and the third group respectively include a single module positioned in a middle of the pack circuit.   
     
     
         16 . The vehicle of  claim 14 , wherein:
 the first group includes one-third of respective battery cells in the pack circuit;   the fourth group includes another one-third of the respective battery cells in the pack circuit; and   the second group and the third group together include a remaining one-third of the respective battery cells of the pack circuit.   
     
     
         17 . The vehicle of  claim 14 , wherein the plurality of switches includes a central switch configured to electrically connect, when in a respective closed position:
 a respective positive leg of the second group to the respective positive leg of the first group; and   a respective negative leg of the fourth group to the respective positive leg of the first group.   
     
     
         18 . The vehicle of  claim 17 , wherein the first configuration is achieved when:
 the central switch is in the respective closed position;   a first load switch and a second load switch electrically connect the pack circuit to the propulsion output;   the respective negative leg of the second group is selectively connected to the propulsion output; and   the respective positive leg of the third group is selectively connected to the propulsion output.   
     
     
         19 . The vehicle of  claim 17 , wherein the second configuration is achieved when:
 the central switch is in a respective open position;   a first charge switch and a second charge switch electrically connect the pack circuit to the DC charge connector;   the respective positive leg of the first group is selectively connected to the respective negative leg of the second group; and   the respective positive leg of the third group to the respective negative leg of the fourth group.   
     
     
         20 . A modular battery system comprising:
 a battery pack having multiple battery modules and a plurality of electrical cables, the multiple battery modules being electrically interconnected via the plurality of electrical cables in a pack circuit, the multiple battery modules being divided into a first group, a second group, a third group and a fourth group;   a direct current (DC) charge connector configured to electrically connect the battery pack to an off-board DC fast-charging station, via the plurality of electrical cables, the battery pack being selectively connectable to a propulsion output;   a plurality of switches selectively connecting the multiple battery modules, the pack circuit being adapted to switching between a first configuration and a second configuration based on a respective position of the plurality of switches, the plurality of switches including a central switch;   a controller having a processor and tangible, non-transitory memory on which instructions are recorded, the controller being adapted to select the respective position of the plurality of switches to transition the pack circuit between the first configuration and the second configuration, in response to input signals indicative of a requested operating mode of the battery pack;   wherein respective battery cells in the pack circuit are arranged in a combination of series and parallel interconnections;   wherein the first configuration provides three parallel electrical pathways, and the second configuration provides two parallel electrical pathways, the parallel electrical pathways referring to individual ones of the respective battery cells arranged in parallel, or groups of the respective battery cells arranged in parallel;   wherein the first configuration is achieved when the central switch is in a respective closed position, a respective positive leg of the first group is selectively connected to a respective negative leg of the second group, and the respective positive leg of the third group to the respective negative leg of the fourth group; and   wherein the second configuration is achieved when the central switch is in a respective open position, the respective negative leg of the second group is selectively connected to the propulsion output, and the respective positive leg of the third group is selectively connected to the propulsion output.